Achieving high reliability in Aerial-Terrestrial networks: Opportunistic space-time coding

Abstract

To rapidly deploy a communication network in the aftermath of disaster or emergency event, an Aerial-Terrestrial architecture integrating aerial base stations mounted on the balloons has been investigated in EU FP7 ABSOLUTE project. Since the signal coverage provided by aerial base stations is patchy and unstable, the opportunistic relaying is applied to increase the link reliability and the system robustness. However, the performance of relay selection drastically degrades due to the outdated Channel State Information (CSI) from the feedback delay over the Aerial-to-Terrestrial radio channels. In this paper, therefore, we present a novel method named opportunistic spacetime coding (OSTC) to combat the outdated CSI. The link reliability in terms of outage probability is evaluated using both Rayleigh channels and the realistic models of Aerial-to-Terrestrial and Device-to-Device channels. The numerical results reveal that OSTC obviously outperforms the opportunistic relaying in the presence of outdated CSI. Moreover, the improvement of reliability comes without any sacrifice in the spectral efficiency.

The Road Towards 6G: A Comprehensive Survey

“…HAP, a quasi-stationary aerial platform operating in the stratosphere at an altitude between 17 km to 22 km above the Earth's surface represents a new alternative to provide a multitude of telecommunication services in a cost-efficient way [141]. In comparison with terrestrial base stations, HAP can cover a larger area, offer unobstructed connectivity with high signal arrival angle, and provide the flexibility of quick deployment with less temporal and spatial constraints [142]. Compared to satellite systems, HAP has the following advantages: much lower cost of implementation and deployment due to the avoidance of space launching, the possibility of upgrading, repairing, and redeployment, and much shorter propagation distance that corresponds to higher signal strength and lower latency [143].…”

Predictive Relay Selection: A Cooperative Diversity Scheme Using Deep Learning

“…Following the working assumption applied for most of prior research works [2]- [12], we consider a dual-hop decode-andforward (DF) cooperative network where a single source node s communicates with a single destination node d with the aid of K relays. Each node is equipped with a single antenna that is used for both signal transmission and reception over a narrow-band channel.…”

“…A direct comparison of different schemes is not easy and does not provide real insight. That is why most of the works in this field [2]- [12] did not provide a quantitative analysis. On the other hand, the complexity of the proposed scheme comes mainly from the DL-based predictor, which is always a concern for the application of deep learning.…”

“…The authors of [9] proposed a method utilizing the knowledge of channel statistics, getting only a marginal gain, whereas the complexity obviously grows. By far, opportunistic space-time coding (OSTC) proposed by the author of this paper in [10]- [12] is the best method in fast fading channel from the perspective of diversity-multiplexing trade-off. But its performance gap to perfect selection using the perfect knowledge of channel is still large, motivating our follow-up works presented here.…”

A Comprehensive View of the Initiatives on the Research of Sixth-Generation Mobile Systems

“…HAP [43], [44] At the altitude of 20km, it provides cost-efficient, flexible deployment with large coverage for new applications.…”